The present invention relates to a drive unit for an elevator comprising motors and a traction sheave wherein the traction sheave and the motors are supported on bearing end-plates arranged on a machine frame.
There is shown in the European patent application EP 0 565 893 a drive unit for elevators which, between two bearing end-plates, has a traction sheave and electric motors which can be mechanically coupled in series. The rigidly series-coupled external-rotor motors are synchronized by means of a multi-motor speed control. The traction sheave and the motors are supported on a rigid axle supported by the bearing end-plates.
A disadvantage of this known device is that the forces acting on the rigid axle are unfavorably distributed. The main forces emanating from the traction sheave must largely be absorbed by the bearing end-plate. Also, the series-coupled electric motors make large distances between bearing end-plates necessary.